president obama will address the united nations. both candidates will attend president clinton's global initiative. and the president and the first lady stopped by "the view." barbara walters is here to speak to that. but first, let's get to jake tapper with more on the president's u.n. speech. good morning, jake. >> reporter: good morning, george. mitt romney and paul ryan will be kicking off a bus tour in ohio, to regain momentum in a state where they're trailing. but president obama will be at the united nations, telling the assembly of leaders that the united states will do what we must to prevent iran from obtaining a nuclear weapon. a senior administration official tells abc news this morning in new york city, in front of the united nations, president obama will reiterate the u.s. commitment to preventing iran from acquiring a nuclear weapon. he'll also call on leaders in the combustible muslim world to end the violence and declare the u.s. will not shrink from bringing to justice those who harm americans. sensing an opening,